Damper construction



R. c. SABINS 2,264,590

DAMPER CONSTRUCTION Y Filed May 15, 1940 b. k in.

. INVENT OR.

Rolland 6-? 542174725,

. Patented Dec. 2, 1941 UNl'l'ED STATES PATENT OFFICE DAMPERCONSTRUCTION Rolland O. Sabina, Wisconsin Rapids, we. Application May13. 1940, Serial No. 334,721 (01. 236-45) 6 Claims. This inventionrelates to a new and improved damper construction and more particularlyto a rigidly constructed damper support with a to control draft bypermitting greater or less in flux of air. into the flue or stovechamber. with greater amounts of air flowing through the damper theefiective' draft on the burner or fire pot is reduced while when thedamper is closed the effective draft is increased.

While the present invention may be used in connection with dampershaving manually adjustable damper weights, it is particularly applicablefor use with thermostatically controlled dampers of the type shown in mycopending application Serial No. 256,448 flied February 13, 1939.

Dampers of this general type must be mounted so as to swing freely ontheir pivots so as to vary the effective damper opening upon slightchanges in draft or temperature conditions. Where the damper is mountedin a damper frame made of light sheet metal there is a tendency for thedamper frame to be forced out of round upon its insertion in the flue orstove openings. Also in use the damper frame may become distorted due towarping of the supporting structure upon repeated heating and cooling inuse. Such warping or distortion of the damper frame may move the damperpivots out of alignment or cause a binding action by taking up thenecessary clearances between the frame and the damper. These actions mayresult in binding the damper so that it does not operate properly or itmay be locked and fail to function at all.

It is an object of the present invention to provide a damperconstruction in which the damper frame is rigidly braced to preventdistortion.

It is a further object to provide bracing of such a character that itforms a portion of the hinge support structure and facilitates assemblyof the apparatus. a

It is also an object to provide spacing means in combination with thebracin so that the damper is definitely located relative to the frameand properly spaced therefrom.

' which- Figure l is a face view of the damper construction as seen fromthe outside;

Figure 2 is a view similar to Figure l but showing the damperconstruction as seen from the in- It isanother object to provide bracingmeans "which also acts as stop means for limiting movement of the dampervane in either direction and which does not substantially obstruct theeifection which is simple in design and side of the stove or flue withwhich it is associated;

Figure 3 is a view of the construction of Figure 1 as seen from above,parts being broken away to show the construction more clearly;

- Figure 4 is a vertical section taken on line 4-4 of Figure 1; and a vFigure 5 is a fragmentary section taken on line 5-5 of Figure 1.

In the drawing, the damper frame II is shown as comprising a cylindricalflange I2 adapted to seat in a flue opening or in a circular opening ina stove construction. The damper frame is provided with a fiat outerflange I3 adapted to seat against the supporting structure to limit itsinward movement relative thereto. It is further provided with aninwardly located inturned flat flange M which closes a portion of theflue opening and also serves as a support for the brace member anddamper hinge'construction. The brace member I5 is shown as a unitarymember formed of pressed steel extending transversely across the openingin the damper frame, and with its ends riveted at 16 and I! to theflange Id of the frame.

The brace member I5 is shown in plan view in Figure 3 and in section inFigure 4. This member extends rearwardly behind the damper vane 18 atapproximately the line of the bearing supporting the vane for pivotedmovement. The member I5 is provided with the depressed portions l9 and20 which are opposite similar depressed portions 2l and 22 formed in theflange I4 of the damper frame ll. pressed portions serve as bearings forthe pivot members 23 and 24 which are secured to the damper vane [8 andextend into the bearings. The brace member I5 is also provided withinturned ears 25 and 26 which pass inwardly opposite the bearings andare provided with perforations in alignment with the bearings. The ears25 and 26 serve also as spacing elements to keep the damper vane l8located concentrically in the composed of at opening in the damper frameII. This main- These opposed de- I ing frame.

tains the damper in proper relationship so that it does not bind or haveits edges engaging the edges of the opening at any point.

As shown in Figures 2 and 3, the brace member I5 is provided withportions 21 and 28 which engage the inner face of the damper slightlyabove the pivot when the damper is in vertical position. They preventthe damper from swinging in such a direction that the top of the dampermoves inwardly, with the bottom of the damper moving outwardly. As shownin Figure 4, the member is also provided with a downturned flange 29which is adapted to engage the rear face of the lower portion of thedamper when that portion swings inwardly to limit such inward movementof the damper. The brace member is provided with inturned edge flanges30' and ii and with the corrugated portions 32 and 33 to assist inmaking the member more rigid.

The damper vane I. has a bi-metallic strip 34 secured thereto by rivet35, this strip being 10-- cated on the outer face of the damper. Theweight rod 36 is threaded through the upper end of-the strip 34 and isprovided with a lock nut 31 to maintain it in adjusted position. The rod36 carries the knurled adjusting knob 38 and the weight 39. The rod 36extends through an opening 40 in the damper II and the weight 39 islocated inwardlycf the damper. As is shown in the drawing, especiallyFigure 2, the brace member I5 is provided with an intermediate U- shapedcutaway portion 4| to permit this location of the weight 39 and topermit it to move freely without engaging the cross brace.

The cross brace is important in that it provides a rigid supportingstructure for the swin ing damper. This prevents the damper frame frombeing distorted or pressed out of round in its installation or duringuse, which distortion would tend to bind the damper or render itentirely inoperative. The cross member also provides pivoted bearingsfor the damper which are permanently aligned and permit free operation.In addition, the cross brace is provided with inturned ears havingperforations which serve as supplemental bearings, while the ears,themselves, have the important function of maintaining proper spacing ofthe damper in its support- This proper spacing prevents binding betweenthe edges of the damper and the frame.

The construction is particularly adapted for use in connection with athermostatically controlled damper of the type shown. Such dampers maybe accurately balanced by proper adjustment of the weight and must befreely movable in their bearings when the counterbalance weight is movedby the thermostatic support under the influence of changes intemperature. The bimetallic strip 34 is of such a character that whenthe strip becomes heated it tends to curve to the right, as shown inFigure 4, the strip thus moving in toward the body of the damper l8.This serves to move the weight 39 to the right,

increasing itseffective lever arm which holds the upper portion of thedamper is against the stop portions 2'! and 28 of the cross bracemember. This greater effect of the weight 39 requires a greater draftwithin the flue or stove in order that the damper'may be swung towardthe open or dotted line position shown in Figure 4.

It will be understood that Figure 4 shows the extreme limit of openingmovement and that in normal use and operation the damper may onlyfluctuate slightly from the vertical. With the necessary to take care ofincreased combustion in the stove. The amount of combustion in a stoveusing an oil burner is controlled by adjustment of the oil feed valve.

The damper itself is a secondary control serving to vary air admittedtoprovide proper draft for the amount of fuel to be burned. This istaken care of automatically in the damper provided with the thermostaticcontrol, since increased heat swings the thermostatic element 8| in suchmanner as to tend to close the damper or maintain it nearer the closedposition, i

when the thermostatic damper is used in connection with stoves orheaters burning solid fuel. the damper may be the primary control sincethe fuel feed is ordinarily not continuously controlled when burningsuch fuel. In this case the thermostatlc element 34 may be installedfacing in the opposite direction, since the draft requirements are theopposite of those with an oil burner. With a solid fuel burner it isnormally desirable to increase the draft when the flre is low, in orderto increase the amount of combustion. Thus it is desirable with suchstoves to increase the draft when the thermostatic element becomes coldand to reduce the draft when the thermostatic element becomes hot. Itwill be understood that the damper may be designed and applied to an;type of stove or heater using any kind of The location of thethermostatic strip 34 outside of the flue has important advantages. Itprevents corrosion of the strip by the flue gases and prevents it frombecoming coated with an insulating layer of soot. v It has theadditional valuable feature of permitting the .control to be partlyresponsive to the temperature of the surrounding air rather than solelyresponsive to the flue gases. This is particularly important when thedamper is applied to a stove serving cally' controlled damper, it may beused with dampers provided merely with manually adjustable weights orcounterbalances and will insure proper operation of such dampers freefrom binding caused by distortion or by engagement of vane withportionsof the supporting strucure.

While I have shown one preferred form of my invention. this is to beunderstood to be illustrative only as it is capable of change to meetdiil'ering conditions and requirements and I contemplate suchmodifications as come within the spirit and scope of the appendedclaims.

What is claimed is:

1. In a damper construction, a damper frame, an elongated brace memberextending transversely of the frame and with its ends secured thereto,and a damper pivotally supported in the frame and brace assembly, thebrace member extending parallel to the pivotal axis of the damper havingstop portions extending upon opposite sides of the damper pivot to limitmovement of the damper in either direction.

2. In a damper construction, a damper frame having an opening therein,an elongated brace member extending across an intermediate portion ofthe frame opening and having its ends secured to the frame, a damperpivotaiiy mounted in the frame and brace assembly within the frameopening, and intumed ears on the bracemember extending into the frameopening at the periphery of said damper between the edge of the damperand the damper frame to space the damper in said opening.

brace member extending into the frame opening at the periphery of saiddamper to space the damper in said opening, the ears being perforatedand the damper having pivot members extending through said perforations.

4. In a damper construction, a damper frame having an opening therein, abrace member extending transversely of the frame and having its endssecured to the frame, the brace ends and frame having opposed depressedportions forming bearings, and a damper fitted in the frame opening andhaving pivot members fitting in said bearings.

' 5. In a damper construction, a damper frame having an opening therein,a brace member extending transversely of the frame and having its endssecured to the frame, the brace ends and frame having opposed depressedportions forming bearings, and a damper fitted in the frame opening andhaving pivot members fitting in said bearings, the brace member havingstop portions to be engaged by the damper to limit damper movement ineither direction.

6. In a damper construction, a damper frame having an opening therein, abrace member extending transversely of the frame and having its endssecured to the frame, the brace ends and frame having opposed depressedportions forming bearings, the brace member having intumed earsextending within the frame opening, said ears having perforationsaligned with the bearings, and a damper fitted in the frame openingbetween the ears and having pivot members extending through theperforations and fitting in said bearings.

- ROLLAND C. SABINS.

